Wireless networks tend to not be either energy or bandwidth efficient. This is due to a lack of fundamental understanding of how to share wireless media among spatially distributed users. Historically, wireless channel access research has followed either a traditional information-theoretic approach that assumes perfect user coordination and ignores the modularized network architecture, or a traditional network-theoretic approach that largely focuses on access control protocols and ignores the impact of the physical layer.

Ephremides’ research will bridge the gap between these two approaches by developing a theoretical foundation for channel access in distributed wireless systems. He will extend classical information theory by developing a channel coding theory for physical layer distributed communication, where users do not jointly design channel codes. At the same time, he will extend classical network theory by developing a medium access control (MAC) framework for distributed networking, where physical layer properties, such as joint multiuser message decoding and flexible adaptation of communication parameters, are efficiently exploited at the link layer. His work should significantly improve the energy and bandwidth efficiency of wireless systems.